Penjelasan dengan langkah-langkah:

Segitiga ABC dengan koordinat A(2,-3), B(-3.2) dan C(-1,-1)

dicerminkan terhadap garis y = -x dan hasilnya dicerminkan terhadap garis x=-5

Ditanya :

Koordinat titik sudut bayangan segitiga tersebut!

Jawab :

Titik A (2,-3) dicerminkan terhadap garis y = -x

x' = -y

x' = - (-3)

x' = 3

y' = -x

y' = -2 => A' (3, -2)

Titik A' (3, -2) di cerminkan terhadap garis x = -5

x' = 2h - x

x' = 2 (-5) - 3

x' = -10 - 3

x' = -13

y' = y

y' = -2 => A" (-13, -2)

Titik B (-3, 2) dicerminkan terhadap garis y = -x

x' = -y

x' = -2

y' = -x

y' = -(-3)

y' = 3 => B' (-2, 3)

Titik B' (-2, 3) dicerminkan terhadap garis x = -5

x' = 2h - x

x' = 2 (-5) - (-2)

x' = -10 + 2

x' = -8

y' = y

y' = 3 => B" (-8, 3)

Titik C (-1, -1) dicerminkan terhadap garis y = -x

x' = -y

x' = -(-1)

x' = 1

y' = -x

y' = -(-1)

y = 1 =>  C' (1, 1)

Titik C' (1, 1) dicerminkan terhadap garis x = -5

x' = 2h - x

x' = 2 (-5) - 1

x' = -10 - 1

x' = -11

y' = y

y' = 1 => C" (-11, 1